"The original idea of this space plane was to destroy the enemy's sputniks," says Vladimir Shcherbakov, deputy editor of Vzlyot (Liftoff), a leading Russian aerospace journal.
"It's a kind of space fighter. If your enemy loses all his sputniks – which provide his communication, intelligence, navigation, etc. – he will be in a panic, he'll be helpless. So it's critical, if you're going to build one, that you state what it's for and whom it's directed against," he says. "The Americans haven't declared who their X-37 is to be used against. They just say they're developing new technologies."
Mr. Shcherbakov says it's quite likely that Russia is working on its own space plane, since the Kremlin nowadays identifies successful space projects as key to boosting Russia's international prestige and has spent a lot more money on the once-moribund space industry.
"Nowadays there's more financing, so the search for cutting-edge projects that we can accomplish is going on intensively," he says. "When the Boeing X-37 was tested, it raised questions from the bosses about whether we were building one, too. But this is a secret subject in the US, and even more so here. So no one will tell you for sure."
The once-mighty Soviet space program virtually collapsed during the 1990s, and its only big remaining project is to act as a kind of "space taxi" to ferry astronauts to the International Space Station.